Many pollutants alter development, growth, survival and reproduction of organisms. As free-living and fast-developing organisms, fish larvae are highly susceptible to pollutants in the environment. For my Ph.D., I am testing the overall question: "Do environmentally realistic levels of currently used pesticides adversely affect the life expectancy of coastal fish larvae?" For this purpose I am studying the eco-physiological consequences of aqueous exposure to the herbicide atrazine and the insecticide malathion on the early life stages of red drum (Sciaenops ocellatus). Atrazine and malathion are among the most widely used organic pesticides, with 65 to 75 million pounds, and 20 million pounds of active ingredient per year, respectively. Although their persistence is moderate to low, they are relatively soluble and have low sorption coefficients. These properties make them a potential contaminant of seagrass beds that are red drum nursery areas.

     Sublethal levels of pollutants, considered as “safe” levels, can have a profound effect on the survival skills of larvae (performance and metabolism) with further effect on the adult population. In the experimental approach, red drum (Sciaenops ocellatus) larvae are directly exposed to water contaminated with known contaminant concentrations that reflect the existing environmental loadings observed in Texas coastal waters. Larvae exposed to contaminants are tested to evaluate their ecological performance, metabolism, growth, and development. The performance trials include measurement of routine swimming and burst responses to predatory stimulus. The metabolism and growth studies will involve measurements of oxygen consumption and biochemical correlates of growth (RNA/DNA and protein turnover).



Publications and Conference Presentations

Alvarez, M. del C.  (2000).  Growth and survival skills of Atlantic croaker, Micropogonias undulatus, larvae following parental exposure to Aroclor 1254. Poster presentation at the 24^th Larval Fish Conference, Gulf Shores, Alabama. 

Alvarez, M. del C.  (1999).  Social hierarchy effect on the physiology of newly metamorphosed juveniles of Japanese flounder.  Poster Presentation at the 23^rd Larval Fish Conference, Beaufort, North Carolina. 

Alvarez, M. del C.  (1998).  Factors affecting digestive function of Japanese flounder, Paralichthys olivaceus, larvae and early juveniles. MS Thesis. Grad School of Agriculture, Kyoto University, Japan.

Alvarez, M. del C.  (1997).  Effects of food quality and quantity on the digestive enzyme activities in Japanese flounder (Paralichthys olivaceus) larvae and early juveniles.  Oral Presentation at the Annual meeting of the Japanese Society of Scientific Fisheries, Hiroshima.